Apparatus for inspection of articles by means of x-ray photographs



Dec. 21, 1948. w. J. DALY 2,456,815

APPARATUS FOR INSPECTION OF ARTICLES BY MEANS OF X-RAY PHOTOGRAPHS Filed Jan. 23, 1945 2 Shee tsF-Sheet 1 4 Dec. 21, 1948. w J DALY 2,456,816

APPARATUS FOR I NS PECTION OF ARTICLES BY MEANS OF X-RAY PHOTOGRAPHS Filed Jan. 23, 1945 2 Sheets-Sheet 2 Patented Dec. 21, 1948 UNITED STATES PATENT OFFICE APPARATUS FOR INSPECTION OF ARTICLES BY MEANS OF X-RAY PHOTOGRAPHS Webster James Daly, Los Angeles, Calif.

Application January 23, 1945, Serial No. 574,090

Claims.

This invention relates to apparatus for the inspection of objects by X-ray photography by means of which large numbers of relatively small objects can be rapidly and efficiently photographed and the photographs compared with the objects in their original positions of exposure, thus rendering the comparison of a photographic negative with the particular objects absolutely certain, assuring both speed and accuracy in the process.

The object of the invention is to provide improved and simplified apparatus for the rapid and efficient production of X-ray photographs of a large number of objects for inspection purposes.

A further object of the invention is to provide apparatus of the character indicated, with operating means automatic in character, so that the entire process of assembling the objects to be inspected with the photographic film in a predetermined order, the photographing of the objects by exposure to X-ray tubes, the development of the films, and the comparison of the films with the objects as originally arranged can be carried out in sequence and predetermined order with the maximum efficiency in each step and by mechanism controlling the sequence of operations, all controlled by a single switch which need be operated only to repeat each cycle of the process.

Further objects will more particularly appear in the course of the following detailed description.

The invention consists in the novel construction, arrangement and combinations of parts hereinafter more particularly described and claimed.

Two sheets of drawings, largely diagrammatic, accompany this specification as part thereof, in which like reference characters indicate like parts throughout.

In the drawings:

Figure 1 is a front elevation of the apparatus;

Figure 2 is a plan view;

Figure 3 is a vertical, longitudinal cross-section through the three station compartments;

Figure 4 is a transverse, vertical cross-section taken on line 44 of Figure 3;

Figure 5 is a diagrammatic layout of the wiring and switches for controlling the device;

Figure 6 is a perspective of an individual film holder; and,

Figure 7 is a fragmentary showing of a pair of doors illustrating the notches for receiving the car connecting rods.

In accordance with the present invention there are provided three longitudinally aligned lightproof compartments designated as I, 2 and 3,

which compartments are provided with communicating passages in the intermediate walls and also in the opposed end walls through Which an articulated chain of cars 6 can pass each of the passages for said articulated cars in the ends and the separating partitions of the compartments being provided with closures herein illustrated as sliding doors 44.

Provision may conveniently be made for access to the compartments I, 2 and 3 through doors I9-I9 for operators and attendants.

The articulated cars 6 are adapted to roll 0 a platform 5 which extends through the station compartments I, 2 and 3, and the cars 6 are connected by pivot links 9 and are arranged to form an endless chain as is well illustrated in Figure 2.

Each of the cars comprises a platform carrying oppositely inclined table members I5) disposed at an obtuse angle. Each of the cars 6 is provided with ground contacting rollers II and with side rollers I2 by means of which the cars are guided and pockets are provided under each of the table tops I0 to receive film supporting shelves I4 which are formed with finger grasp and light-excluding cleats I3 on their forward edges by means of which photographic film can be inserted under each of the table tops I0 parallel with and closely adjacent to the table tops.

Sprocket wheels I5I 5 are positioned as herein illustrated on each side of the station compartments, these sprockets I5 being proportioned to engage adjacent cars 6, the cars being connected and articulated as by connecting rods 9. The chain of articulated cars is driven as by a motor I8 and belt or chain II passing over a pulley I6 fixed with respect to one of the sprocket wheels I5.

All of the sliding doors 4 are operated by a common drive shaft 24 which extends within and throughout the length of the three station compartments I, 2 and 3. The shaft 24 is driven from a motor 28 as by a belt 26 passing over a pulley 21. The shaft 24 is positioned above and to one side of each of the pairs of folding doors 4 and horizontally aligned with shaft 24 upon each of the partitions providing passageway for the cars 6 is mounted a stub shaft 24 carrying a sprocket wheel 23. Endless chains 22 pass over the sprocket 23 and similar sprockets mounted on shaft 24 and the chain 22 is connected from its opposite sides with the doors of each pair as by arms 2| extending from each of the doors. The rotation of shaft 24 in opposite directions is controlled by a reversing switch for motor 28 which is positioned over one of the pairs of doors 4 and indicated as M. The throw lever 30 of switch 3| is adapted to be engaged by spaced lugs 29-29 secured on the lower reach of chain 22, which lugs 29 are spaced corresponding to the width of the doors 4 so that the switch 3! will be closed to operate the motor 28 in the fully closed and fully opened position of doors 4 only.

Each pair of doors 4 has the inner edge of each door notched as at 10 and provided with complementary gasket parts 7| adapted to seat tightly around the connecting links 9 between cars on opposite sides of each partition.

The motor I8 used for driving the chain of cars is controlled by a switch 45 positioned on the platform adjacent the line of travel of the chain of cars adapted to be successively thrown by engagement with a bracket 44 extending from the side of predetermined cars herein illustrated as every second car and a suitable brake 50 is associated with the motor l8 adapted to positively check and hold the line of cars in their successive positions.

Within the first compartment, herein illustrated' as the left-hand compartment and con-- sidered with reference to the direction of travel of the cars 6, are positioned a plurality of film shelves 32 above and conveniently reached by an operator standing in front of the line of cars. Each of these film shelves is protected by a hinged door 33 which may be lifted to remove fresh films conveniently to the several cars within the compartment I. Also in this compartment the operator will arrange the objects to be photographed and inspected upon the tops of the tables In of the respective cars, it being desirable that where a plurality of objects are to be photographed together they may be arranged in accordance with a standardized plan upon each table top. The objects herein are illustrated and referred to as 0; The operator, having arranged the objects upon the table tops of the respective cars, will, asindicated, withdraw fresh films from the film shelves above the cars, place the films upon the fllm shelves i4 withdrawn from under each table top H) and replace the same under the table tops. With the objects thus arranged and the films positioned on each of the cars Within compartment I, the operator there will close a master switch positioned in said compartment, which will operate to start an automatic cycle of operation as hereinafter more particularly described. In general the movement of the sliding doors 4 to their fully opened position will conclude an automatic cycle of operation. Closing switch 40 will start the motor l8 and cause the cars to advance until two cars are Within the middle compartment 2 wherein are located two X-ray tubes 35, each ositioned above one of the cars 6 and so arranged with respect to the inclined table tops III of these two cars to direct the X-rays 31 substantially perpendicularly to the objects and the photographic film associated with each car. At this point the doors will be closed and the X-ray lamps energized. The operation of the X-ray tubes 36 is controlled by a timer, in conjunction with the door and car operating circuits so that at the conclusion of the proper exposure interval the current will be turned off from the X-ray tubes 36 and motor 28 energized to again open all of the sliding doors 4, which concludes the cycle.

In a right-hand compartment 3 is positioned developer apparatus 38 and the exposed films can be removed from under the respective table tops l0, developed, and replaced each on its proper table top, to be carried with each car as it passes from the right-hand compartment 3.

An inspection station 34 will be conveniently located anywhere along the line of travel of the chain of cars, exterior of the light-proof compartments, and at this inspection station an operator can remove from each table top the developed X-ray film of the objects on that particular table top and examine the same, in connection with which examination it will be noted that the objects on each table top will occupy the same position in which they were placed in compartment I so that the detection of particular defective objects is greatly simplified by reason of the continued close association of each film with the objects through all steps of the process.

To operate the motors and X-ray tubes in the proper sequence, an electrical circuit is illustrated in Figure 5, in which a primary circuit carrying 220 volts is shown for the operation of the driving motors for the chain of cars, doors and X-ray tubes, and a secondary circuit of volts is provided for the operation of the switch operating solenoids.

With the doors 4 of the compartments open and the circuit as shown in Figure 5, the cycle of operation will be commenced by an operator closing the contact switch 40, which momentarily closes the circuit of solenoid 4!, thus throwing pivoted switch arm 42 to the left to close the circuit through wires 43-43 starting motor l3 and thus starting in motion the train of cars 6. When the cars have advanced the length of two cars, the bracket 44 positioned on one of the cars will depress switch 45, closing the circuits of solenoids 46 and 41,

The closing of solenoid 46 will swing switch arm 42 to the right, breaking the circuit of motor IB and closing the circuit through wire 48 with solenoid 49 operating brake 50.

The energizing of solenoid 47 simultaneously with energizing solenoid 46 by switch 45 swings pivoted switch arm 5| to the left, thereby closing the circuit through switch arm 51, contacts 52 and 53 through the reversing switch arm 30 and contact 54 to operate door motor 28 to rotate shalt 24 and close all of the doors 4. As the doors reach their closed position the lug 29 reverses switch arm 30 to form contact with the contact points it and H and at the same time link 55 pivoted to switch arm 30 will immediately close switch 57 to complete circuit 58, energizing solenoid 59 which will attract spring controlled pivoted arm 50 to engage timer Bi and start said timer, which will close circuit 62, thereby energizing solenoid 63 which will attract spring controlled pivoted arm 64 to engage contact 65 and close the circuit 56 to the X-ray tubes 36, thus starting the exposure of the films positioned on the two cars within compartment 2. At the expiration of the time for which the timer is set the current through circuit 62 will be broken, thus ci e-energizing so1cnoid 63 to permit spring controlled pivoted arm 6 to throw pivoted arm 55 to the left to su ch 61, thereby energizing solenoid 63 which draws pivoted arm 5! back to its initial position. closin the circuit to operating motor 28, to open the doors. As the doors reach the fully open position, reversing switch arm 30 is thrown to break the circuit to motor 28, thus completing the cycle with the doors fully open and the circuit as illustrated. The links 55-55' associated with the switch arms 30 and 54 are illustratedas provided with pivoted lugs 52 adapted to operate switches 57 and 6'! as they pass over those switches in one direction but to ride freely over said switches without operating same in the opposite direction.

What I claim is:

1. Apparatus for inspecting objects by X-ray photography in which the inspection station is remote from the photographing station, comprising a conveyor consisting of a chain of tables each of X-ray permeable material on which one or more objects to be inspected are laid, means beneath each table for removably holding a photographic film, there being successive positional areas along the line of travel of said conveyor through which said conveyor passes, constituting successively a film loading station, an exposure station, a developing station, and an inspection station, means for moving said conveyor step by step so as to present said tables successively with the objects to be inspected unmoved with respect to said tables, first to said film loading station, next to said exposure station where the image of the object is photographed, next to a developing station where the exposed film is removed, developed, and returned to said film holding means, and finally to said inspection station, at which stage the relative positions of the object and its photographed image on the film are the same as they were at said exposure station.

2. Apparatus for inspecting objects by X-ray photography as claimed in claim 1, including articulations between said tables, light-tight compartments separately enclosing at least said exposure station and said developing station, said compartments having openings through which said conveyor passes, sliding doors for said openings constructed to cooperatively close about said articulations, and means for operating said doors synchronized with said conveyor moving means to open said doors at the starting of said conveyor and close them at the stopping of said conveyor.

3. Apparatus for inspecting objects by X-ray photography as claimed in claim 1, including articulations between said tables, light-tight compartments separately enclosin at least said exposure station and said developing station, said compartments having openings through which said conveyor passes, sliding doors for said openings constructed to cooperatively close about said articulations, means for operating said doors syrichronized with said conveyor moving means to open said doors at the starting of said conveyor and to close them at the stopping of said conveyor, an X-ray tube in the light-tight compartment of said exposure station above said conveyor, and energizing means for said tube synchronized with said conveyor moving means for activating said tube at the stopping of said conveyor.

4. Apparatus for inspecting objects by X-ray photography as claimed in claim 1, including an X-ray tube at said exposure station above said conveyor, said tables each having faces lying in planes which define a downwardly directed wide dihedral angle, said faces being symmetrical with respect to a plane through the apex of said dihedral angle, perpendicular to the direction of movement of said conveyor, means controlling said conveyor moving means to stop said conveyor when the axis of the beam from said X-ray tube is coincident with said plane of symmetry.

5. Apparatus for inspecting objects by X-ray photography as claimed in claim 1, including an X-ray tube at said exposure station above said conveyor, said tables each having faces lying in planes which define a downwardly directed wide dihedral angle, said faces being symmetrical with respect to a plane through the apex of said dihedral angle perpendicular to the direction of movement of said conveyor, means controlling said conveyor moving means to stop said conveyor when the position of the axis of the beam from said X-ray tube is coincident with said plane of symmetry, and means for energizing said tube synchronized with said conveyor moving means for activating said tube upon the stopping of said conveyor. 7

WEBSTER JAMES DALY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,169,483 Adrian Aug. 15, 1939 2,298,942 Hicks Oct. 13, 1942 2,306,194 Swaisgood Dec. 22, 1942 

